Haier BD-478A service manual Resonance sound of compressor components

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Freezer noise mainly comes from the compressor. The Compressor generates various sounds. There are continuous and not continuous, periodic and not periodic. Their frequencies may be from tens of Hertz to thousands of Hertz. Reasons for compressor noise are:

(1)There are two pieces thin elastic steel slice inside the compressor (gas in valve and gas out valve), when the freezer starts, each steel slice will open and close about 47 times per second, this will cause vibration sound. At the same time, the open and close of steel slice will contacts other parts and also make sound. The continuous buzz we heard is this kind of sound.

(2)When compressor is produced, there must be clearance between components. When freezer is running, the existing of clearance will make some components touch and gives out sound. Especially, at starting and stopping, the forces acted on compressor components changes greatly and bigger sound will be generated.

(3)Noise of flowing liquid

The running process of compressor is a continuous gas in and out process.

If the pressure of refrigerant gas breathed in or exhausted out changes suddenly, vibration sound will be generated.

MAINTENANCE SERVICE AND TROUBLE SHOOTING Maintenance Service and Trouble Shooting

(4) Resonance sound of compressor components

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Contents BD-478A Contents First letter of Freezer in Chinese spelling Product Code Illumination and Series IntroductionFeatures FeaturesBD-388A BD-478A SpecificationsSafety Precautions Safety Precautions 1420*715*1470 1690*715*1470 Net Dimension1420*715*810 1690*715*810 ·Proper Air Circulation Installation and Accessory PartsElectrical Requirement Installation and Accessory Parts Food Storage Basket Defrosting and Draining The FreezerSystem Flow Chart Function Schedule Adjustable temperature dialBrief description of principle about BD-318A/428A Maintenance Service and Trouble ShootingReasons of electricity leakage of freezer Servicing freezerMaintenance Service and Trouble Shooting Maintenance Service and Trouble Shooting Troubleshooting by sounds Troubleshooting by touch System noise repair Poor freezing effect analysis and solutions How to handle the seal bar for poor sealing How to know there is problem with compressor Motor Why freezer cannot be used at low temperature environmentPage Page Procedure for temperature controller change Procedure for fan changeCommon freezer problems Operation of freezer is not normal Evacuation and fill machine is special only for R134a use Service procedureRepair equipment Requirements Changing procedure of R134a compressor Compressor installation and brazing procedures Product characters Application and maintenance of freezerPage Maintenance Safety notice of productStandard procedure of maintenance 12.5 It is not allowed to fill R134a by R12 filling equipment Freezer repair tool and equipment⑧ Switch off motor Procedure for filling equipmentFilling Freezer noise sourcesCompressor Resonance sound of compressor components Gas flowing sound How is the sound of water flowing generated?Why the freezer’s noise increases after using How to reduce freezer’s noise? Why freezer’s noise increases after stop use for sometime?Why freezer noise changes greater at night? Sometime?What are the national stipulations for freezer Noise? Why freezer noise measured at home is incorrect?Page Answer Why the noises of it type freezers are different?How to determine that the sound is noise or Normal? There are stipulations in Items 6.5.7.1 and 6.3.6.1.of GB/T Noise testMaintenance Service and Trouble Shooting 12.8Measuring technology of freezer performance parameter Test method and instrument Temperature with loadGround resistor Maintenance Service and Trouble Shooting Maintenance Service and Trouble Shooting Maintenance Service and Trouble Shooting Exploded View List of Parts QTY BD-388A/478A 392% 600% Lamp switch BD-388A/478A 010% 020%